See this link in "NBN Wiki"
TPG offer a basic plan for $30 a month, 10 GB data and 12/1 Mbps +$10 for unlimited calls in Australia (not ones starting with 13 though, these are charged for) nor does it support calls to numbers starting with 19.
dodo offer a similar plan that has same data etc
Telstra (these are for the NBN as well). For pensioners on the Home Phone Local plan and above eg National there is also a $15 a month call credit available to help offset pay for calls including numbers starting with 13.
I am sure there will be others but this should give you a good start.
If requiring data then even the phone only plans in the list can be adjusted with the providers to have broadband + phone if needed eg Aussie Broadband
Telstra Broadband bundle with unlimited calls to Australian numbers will start at $80 per month with 100 GB data.
Optus will charge you $70 a month for unlimited Internet + calls to Australian numbers inc mobiles or $65 if mobiles are charged calls. This is with their NBN Speed Pack 1 which is the 12/1 Mbps speed tier.